similar to: Question about instcombine pass.

Hi all, I have a question regarding dynamic indexing into a vector with GEP. I see that in the ScalarReplAggregates pass in the LLVM 3.2 release the call SROA::isSafeGEP() will now allow alloca scalarization in the case where a GEP index into a vector isn’t a constant. My question is: what is the expected behavior when the index is out of bounds of the vector? Is it undefined? I have an

I changed the input C to using a 64 bit type for the loop index (this eliminates 'sext' instructions in the IR) Here the IR produced with clang -O0 define float @foo(i64 %start, i64 %end, float* %A) #0 { entry: %start.addr = alloca i64, align 8 %end.addr = alloca i64, align 8 %A.addr = alloca float*, align 8 %sum = alloca [4 x float], align 16 %i = alloca i64, align 8

Dear R people, I have to deal with the output of a function which comes as a matrix of vectors. You can reproduce the structure as given below: x <- list(c(1,2,4),c(1,3,5),c(0,1,0), c(1,3,6,5),c(3,4,4,4),c(0,1,0,1), c(3,7),c(1,2),c(0,1)) data <- matrix(x,byrow=TRUE,nrow=3) colnames(data) <- c("First", "Length", "Value") rownames(data)

But even for a very simple loop: int test1 (int *x, int *y, int *z, int k) { int sum = 0; for (int i = 10; i < k; i++) { z[i] = x[i] / y[i]; } return sum; } The initial value of induction variable is not zero after compiling with -O3 -mcpu=power8 x.cpp -S -c -emit-llvm -fno-unroll-loops (see bottom of the email for IR) Also I can write somewhat more complicated loop where step

Hi, I am trying to understand LLVM vectorization implementation and was looking into both loop and SLP vectorization. test case 1: *int foo(int *a) {int sum = 0,i;for(i=0; i<16; i++) sum += a[i];return sum;}* This code is vectorized by loop vectorizer where we calculate scalar loop cost as 4 and vector loop cost as 2. Since vector loop cost is less and above reduction is legal to

Dear R users: I just got confused some R code used in linear mixed model~ example,two factors,A, B,C,A is fixed ,B,C are random,and B is nested in C,if I wannt to use linear mixed model,are the following code correct for each case? case1:want to know random effect of B, case1<-lme(y~A*B*C,random=~B|C) where "B|C" stand for what?,mean B is nested in C? case2: how to wirte

Hi Nadav, Thanks for the quick reply !! Ok, so as of now we are lacking capability to handle flat large reductions. I did go through function vectorizeChainsInBlock() (line number 2862). In this function, we try to vectorize if we have phi nodes in the IR (several if's check for phi nodes) i.e we try to construct tree that starts at chains. Any pointers on how to join multiple trees? I

Hi Arnold, Thanks for your reply. I tried test case as suggested by you. *void foo(int *a, int *sum) {*sum = a[0]+a[1]+a[2]+a[3]+a[4]+a[5]+a[6]+a[7]+a[8]+a[9]+a[10]+a[11]+a[12]+a[13]+a[14]+a[15];}* so that it has a 'store' in its IR. *IR before vectorization :*target datalayout = "e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128" target triple =

Hi Suyog, Thanks for looking at this. This has recently got itself onto my TODO list too. > I am not sure how much all this will improve the code quality for horizontal reduction > (donno how frequently such pattern of horizontal reduction from same array occurs in real world/SPECS). Actually the main loop of 470.lbm can be SLP vectorized like this. We have three parts to it: A fully

On Tue, Dec 19, 2017 at 9:10 AM, Siddharth Bhat via llvm-dev < llvm-dev at lists.llvm.org> wrote: > I could be entirely wrong, but from my understanding of memorySSA, each > def defines an "abstract heap state" which has the coarsest possible > definition - any write will be modelled as a "new heap state". > This is true for def-def relationships, but

Hi, I am new to MemorySSA and wanted to understand its capabilities. Hence I wrote the following program (test.c): int N; void test(int *restrict a, int *restrict b, int *restrict c, int *restrict d, int *restrict e) { int i; for (i = 0; i < N; i = i + 5) { a[i] = b[i] + c[i]; } for (i = 0; i < N - 5; i = i + 5) { e[i] = a[i] * d[i]; } } I compiled this program using

Dear R users: I am having difficulty to place x-axis location alternatively top/bottom side in Lattice plot, which is composed of seven-column as following: E1 E2 E3 E4 E5 E6 E7 Case1 -505.85 -75.32 494.52 -12.31 -98.96 50.34 -48.62 Case2 -50.46 -60.97 68.32 -8.66 -51.77 25.17 -26.60 Case3 -253.00 -54.99 243.48 -8.76

Good morning, I am analyzing a dataset composed by 364 subjects and 13 binary variables (0,1 = absence,presence). I am testing possible association (co-presence) of my variables. To do this, I was trying with cluster analysis. My main interest is to check for the significance of the obtained clusters. First, I tried with the pvclust() function, by using method.hclust="ward" and

Hello, I've some problem with the ggplot2. Here's a small example: --8<-- library(ggplot2) molten <- data.frame(date=c('01','01','01','01', '02','02','02','02'), channel=c('red','red','blue','blue',

Hi, Scalar evolution seems to be wrapping around the trip count in the following loop. void add (int *restrict a, int *restrict b, int *restrict c) { char i; for (i = 0; i < 255; i++) a[i] = b[i] + c[i]; } When I run scalar evolution on the bit code, I get a backedge-taken count which is obviously wrong. $> cat loop.ll ; Function Attrs: nounwind define void @add(i32* noalias

Hi All, I am trying to unroll the below loop, but couldn't as SCEV returns TripCount as 0. void foo(int x) { int p, i = 1; int mat[6][6][6]; for (p = x+3 ; p<= x+6 ;p++) mat[x][p][i] = mat[x][p][i] + 5; } For a quick reference I have added the generated IR compiled with clang using -O3. Please let me know if this is an known issue in SCEV or I am missing something here ? ;

The SLP vectorizer apparently did something in the prologue of the function (where storing of arguments on the stack happens) which then got eliminated later on (since I don't see any vector instructions in the final IR). Below the debug output of the SLP pass: Args: opt -O1 -vectorize-slp -debug loop.ll -S SLP: Analyzing blocks in _Z3barmmPfS_S_. SLP: Found 2 stores to vectorize. SLP:

I was looking at the code generated from the following c code and noticed extra loads in the inner-loop of these nested for-loops: #define DIM 8 #define UNROLL_DIM DIM typedef double InArray[DIM][DIM]; void f1( InArray c, InArray a, InArray b ) { #pragma clang loop unroll_count(UNROLL_DIM) for( int i=0;i<DIM;i++) #pragma clang loop unroll_count(UNROLL_DIM) for( int

I have modified the example test case for UB error, still it didn’t unroll void foo(int x) { int p, i = 1; int mat[9][9][9]; for (p = (x+1) ; p < (x+3) ;p++) mat[x][p-1][i] = mat[x][p-1][i] + 5; } Regard, Deepali From: Kevin Choi [mailto:code.kchoi at gmail.com] Sent: Friday, September 16, 2016 1:20 PM To: Rai, Deepali Cc: llvm-dev at lists.llvm.org Subject: Re: [llvm-dev] SCEV

On Wed, Jul 27, 2011 at 2:28 PM, Matt Johnson <johnso87 at crhc.illinois.edu> wrote: > Hi All, >     I'm writing a backend for a target which only supports 4-byte, > 4-byte-aligned loads and stores.  I custom-lower all {*EXT}LOAD and > STORE nodes in TargetISelLowering.cpp to take advantage of all alignment > information available to the backend, rather than treat each